1. Field of the Invention
The present invention relates to image pickup apparatuses and reproducing apparatuses, and particularly to techniques for changing a compression ratio during moving image shooting.
2. Description of the Related Art
Today, many commercially available cameras are configured to be capable of shooting both digital videos and digital still photographs. However, different pipelines are typically provided for a video recording mode and a digital still image mode. Therefore, a user is required to switch back and forth between the video recording mode and the digital still image mode during shooting. Moreover, even if a frame is extracted from a moving image to obtain a digital still image, the resolution of the frame image taken by using the pipeline for the video recording mode is low.
Japanese Patent Laid-Open No. 2003-283921 (hereinafter referred to as “Patent Document 1”) discloses a method for simultaneously processing digital video frames and high-resolution still images in a burst mode. This method allows snapshots to be taken during moving image shooting.
Japanese Patent Laid-Open No. 2002-300372 (hereinafter referred to as “Patent Document 2”) discloses a technique (super-resolution processing) for combining two images serially taken, thereby achieving high-quality images or images with advanced visual effects.
However, the processing method described in Patent Document 1 is directed specifically to taking snapshots during moving image shooting. The method does not allow a user, during moving image reproduction, to extract a high-resolution frame image at a desired scene from a compressed moving image.
Also, an image processing apparatus described in Patent Document 2 has a disadvantage that if a moving image is recorded at a high compression ratio, such as in the case of a moving image in Moving Picture Experts Group (MPEG) format, the resolution of a composite image generated from a plurality of consecutive frames in a section where there are consecutive predicted frames (P-frames) is low.